A flow control method and system including an algorithm for deciding to transmit an arriving packet into a processing queue or to discard it, or, in the case of instructions or packets that must not be discarded, a similar method and system for deciding at a service event to transmit an instruction or packet into a processing queue or to skip the service event. First and second needles hold respective first and second ends of a suture thread. Pressures upstream, between andor downstream of the valves may be detected and used to determine if one or both of the valves leak when closed. According to the arrangement, since at least a part of the controller is activated intermittently, the consumption of electricity can be reduced. The second portion of the second element is flexible and forms an arm which can be bent to create an electrical connection between the second portion of the first element and the third portion of the second element. The method may also include recording the online chat between the users to define an amendment to the contract in response to the online chat option being selected.